Coumarone-indene resin



June 9, 1942. F. w. coRKERY coUMARoNE-'INDENE RESIN Filed Feb. 9, 1940MMQQDQ Patented June 9, 1942 COUMARONE-INDENE RESIN Frank VW. Corkery.Grafton, Pa., assignor to Pennsylvania Industrial Chemical Corporation,a corporation ot Pennsylvania Application February 9, 1940, Serial No.318,067

Claims.

This invention relates to the-production of a coumarone-indene resin ofa sort suitable for use in mastic tile.

The invention primarily rises from my discovery that the complete resinrecovered from purified aromatic Istill residue which is a waste productoi coal by-product recovery plants, and which is fundamentally acoumarone-indene resin, contains a strictly limited series of thecoumarone and indene polymers, and that the resin may be used as aplasticizer with very high polymer coumarone-indene resin, to give acoumarone-indene blend having a melting point and penetrationcharacteristics which render it suitable for use in binders for mastictile.

First to discuss the still residue resin, the still residue from whichit is derived is a substance residually produced in the fractionationand purication treatments of the light oil recovered in the by-productcoking of coal. 'Ihis light oil comes over in coal distillation. By farthe greatest proportion of the light oil distills over before tar inby-product coking, and is recovered from the gases with which it comesover by being absorbed in a scrubbing oil, which scrubbing oil isusually a heavy cut oi petroleum. The still residue contains polymers ofresin-forming bodies in various stages of polymerization, some heavymonomers, traces of naphthalene, and sulphonate contamination.

As a still residue of this sort is commonly available commercially, itcontains a substantial proportion of sulphonates from the acidpurification and neutralization of the light oil, or light oilfractions, followed by the distillation in the pure stills which resultsin the production of a residue. These sulphonates are in the form ci thealkaline and alkaline earth salts of sulphonates of light oil aromatics;and the alkaline and alkaline earth acid sulphonates of the light oilaromatics. Sulphate addition products and sulphones are 'also present inthe mass of impurities. All are herein included in the general termsulphonates.

denitely in important characteristics from a coumarone-indene resinwhich does not contain sulphonates. Its color depth is about 17 or 18on'the coal tar resin color scale. While usable for some purposes, thissulphonate-contaminated resin, obtained as the solid residuum from thedistillation of unpuried still residue, has qualities which lessen itssuitability for many purposes, prominent amongst which qualities is inits tendency to water-spot when included in mastic tile, and itstendency to be brittle at low temperatures.

In preparing from the still residue a lresin of coumarone-indene sortpurposed inter alia for use in mastic tile, I have, therefore, purifiedthe still residue of its content of sulphonates. initially to obtain aliquid consisting preponderantly of'aromatic solvent and coumarone andindene polymers in various stages of polymerization (i. e. consisting ofcoumarone and. indene polymers containing various diierent numbers ofthe coumarone and indene units). This puriiication may be eiected inseveral ways. For example, it may be eiected by solvent separation, asin my United States Patent No. 2,172,437, dated September 12, 1939, ormay-be by treatment with sulphuric acid and water,` accompanied bygentle heating, as in my co-pending application Serial No. 182,804,iiled December 3l, 1937.

Following removal of sulphonates, there remains initially a stillresidue consisting essentially of the coumarone and indene polymers insolution in the aromatic solvents with which they were associated in thestarting material, and with any aromatic or aliphatic solvent orsolvents, used in the purication. Such puried solution ofcoumarone-indene polymers is subjected to distillation to distill oiisolvent and to recover a yield of resin, either as a complete resincontaining all the series of polymers of the still residue, or a toppedresin from which part,

vor all the dimers of coumarone and indene are removed by distillation.These dimers distill oi under steam and vacuum at a temperature of about220 C., to leave what is essentially a solid coumarone-indene resin,having a melting point of about C. to 105 C. (ball and ring), and havinga molecular weight of about 450.

Since this resin is of good melting point, and is devoid of dimers, itisnaturally to be assumed that it is a resin particularly suitable for usewith gelled oils to provide a binder to be associated with pigment orilller in making mastic tile. It does not, however. tend to give amastic tile in which it is included high penetration resistance attemperatures above normal room temperature and mastic tilev in which itis included tends to differ rather widely in its penetration at 77 F.and its penetration at 115 F.

In seeking to improve the qualities of the resin for such use, Ianalyzed the polymer structure of the resin, and found that it consistsalmost exclusively of coumarone and indene polymers containing 3, 4, and6 units of coumarone and indene. That is, it consists almost exclusivelyof coumarone and indene polymers which I designate as being in the 3rd,4th, 5th, and 6th stages of polymerization. There is an almost totalabdoes not, therefore, have the beneilt of `a content` of high polymerscapable of individual resistance to penetration. I have found that theaddition of higher polymers, independently obtained, to this resinrenders the resin too hard and brittle for satisfactory use in mastictile.

A molecular analysis of the purified still residue resin from which nodimers are removed, shows that it consists about 50% of dimers and about50% of polymers containing 3, 4, 5 and 6 units of coumarone or indene;and that of this latter content the 4th and 5th stage polymers greatlypreponderate. I have-found that, as the still residue is commerciallyavailable, its relative proportion of dimers with the sum of the otherpolymers does not vary much more than 5% either way from theabove-stated proportion.

I have discovered that, although high melting resin may not withsatisfaction' be added to a completely topped still residue resin, tothe extent its initial content of dimers is retained in the resin thatretained content of dimers is usable to plasticize high coumarone-indenepolymers to admit of their addition to the still residue resin. Anysubstantial retention of dimers in the still residue resin, accompaniedby a substantial addition of high melting coumarone-indene resin, isbenecial. By .beneflcial I mean causing increase in those qualitieswhich derive from high viscosity at elevated temperature with respect tothe melting point of the resin. In mastic tile, and also inwire-coatings, such desirable qualities are resistance to penetration atelevated temperature. and flow-resistance at elevated temperature.

To give a concrete example: Dimers in a weight of about 25% the initialweight of the resin were retained, and a high-melting coumarone-indeneresin, such as one having a melting point from 150 C. (ball and ring)upward, was included in a weight somewhat exceeding the weight of theretained dimers. In this blended resin the resistance to penetration atelevated temperature is substantially better than that of a stillresidue resin from which all the dimers are distilled off.

Proceeding on this principle, I have found that the best results areobtained when the total still residue resin is blended with a highmelting resin in as great a proportion of the latter as the dimercontent of the still residue resin is able to plasticize. By tota stillresidue resin I mean a run-of-the-still resin recovered by purifying rawstill residue, and by distilling off its solvent content, but in whichall, or approximately all the dimer content has been retained. Suchstill residue resin is obtained by discontinuing distillation soon afterthe rst appearance of the dipolymer oil of the resin, which is composedalmost exclusively of the coumarone and indene dimers.

The total still residue resin has a melting point within the approximaterange of 10 C. and 20 C., and has a molecular weight within theapproximate range of 300 to 350 and has a color intensity of about 10 onthe paracoumarone resin color scale. Typically I .blend with this totalstill residue resin a high melting coumarone-indene resin of a meltingpoint from about 150 C. (ball and ring) to about 200 C. (ball and ring).Such high melting resin has an average polymer size between 15 unitpolymers and 20 unit polymers, and has a molecular weight of from about1400 to 2500. It has high resistance to penetration both at 77 F. and at115 C. By blending such resins in the approximatev proportion of 60%total still residue resin and 40% of high melting resin, an excellentcoumarone-indene resin for association with plasticizers in a bindercomposition for mastic tile is produced. The resin above described has amelting point of about 95 C. (ball and ring). It will be as'- sumed thatthis blended resin is mixed with plasticizer, such as gelled linseed oilin the standard proportion of 70% of resin and 30% of the plasticizer toform a binder composition for mastic tile, and that mastic tile is madeby mixing this binder with pigment in the standard proportion of 75%pigment to 25% binder. That tile has an indentation value of about 14for 1 minute at 77 F., for 10 minutes at 77 F. it has an indentationvalue of about 18, and for 30 seconds at 115 F. it has an indentationvalue of about 28. A similarly proportioned mastic tile containingdimer-free still residue resin shows an indentation value of about 16for 1 minute at 77 F., an indentation value of about 32 for 10 minutesat 77 F., and an indentation value of about 100 for 30 seconds at 115 F.These penetrations were all taken by the standard indentation machineused by manufacturers of mastic tile.

It will be seen that Whereas the penetration indices of the dimer-freeresin and the blended resin are fairly close to each other, underconditions favorable for resisting penetration, there is a markeddifference in the penetration when continued for a substantial length oftime, and a striking diierence in their penetration indices at elevatedtemperature. 'I'he difference in penetration-resisting properties isintermediate in value if the still-residue resin retains some, but lessthan all, the content of dimers, and is blended with high-polymercoumarone-indene resin in appropriate quantity and of appropriatemeltingand a high melting coumarone-indene resin of the maximum molecularweight and quantity consistent with the plasticizing capacity of thetotal still residue resin.-

Further, I have found that by blending the total still residue resinwith a coumarone resin having an extremely high melting point, such as amelting point of 250 C. and upward, and a molecular weight exceeding3000 in a proportion of of the total still residue resin to 20% of theextremely high melting resin, I produce a blend which may be usedwithout the addition of gelled oil as the binder in mastic tile. Thisresin blend is operative for that purpose on the principle that thesmall proportion of extremely high polymers gives the blend resistanceto penetration while the quantity of dimers introduced with the totalstill residue is adequate to plasticize the blend. The intermediatepolymers, namely those in the 3rd, 4th, 5th, and 6th stages ofpolymerization, may be considered as a ller, or bulkng content, of theresin.

In all proportions of retained dimer content and added high polymerresin plasticized by the dimer content, the blended resin has a higherviscosity at elevated temperature than has astill residue resin of equalmelting point, the melting point of which is dependent upon the removalof dimers rather than upon the addition of high polymer resin. Inexplanation the dimer-free still residue resin above noted, winchconsists of 3rd, 4th, 5th, and 6th stage polymers, has a melting pointof about 95 C., the melting point being relatively so high because ofthe absence of any substantial dimer content. A still residue resinhaving about 25% its weight supplied by retained dimers has a meltingpoint of about 55 C.; and when there is added to it a content of highpolymer resin melting above 150 C. in a quantity equal to about 30% theweight ofthe still residue resin, the blend has a melting point of about95 C. A total still residue having about 50% its weight supplied by itsdimers has a melting point of about 10 C., and when this resin is mixedin the proportion of about`60% of the still residue resin to about 40%of high polymer coumarone-indene resin melting above 150 C., the meltingpoint of the blend is about 95 C.

Whereas these three exemplary resins all have approximately the samemelting point, it has been above explained wherein their penetrationcharacteristics differ widely. The penetration characteristics of theresin and the resistance of the resin to ow at elevated temperature, arefunctions of the viscosity of the resin at elevated temperature, and itmay be said that the blends of still residue resin with high polymercoumarone-indene resin are characterized by having a higher viscosity atelevated tempera-l ture than a still residue of equal melting point, themelting point of which is attributable to the subtraction of dimers togive a resin composed in approximate entirety of the 3rd, 4th, 5th, and6th stage polymers.

It is not possible to state in definite proportions the proportion ofhigh polymer resin to dimers which will render the blend containing thestill residue resin satisfactory for use in ,mastic tile. Because themolecular weight, as

well as the quantity of the high polymer -resin plays a part in theapportionment, the upper limit of included high-melting resin isnecessarily variable. It may, however, be stated as a guide that inblending a still residue resin, composed aside from its dimer content of3rd, 4th, th and 6th stage polymers, with high polymer coumarone-indeneresin having a melting point of between 150 C. and 175 C. the latter maybe included within an upper limit of 4 parts by weight of the highpolymer resin to 3 parts by weight of the dimer content of the stillresidue resin. With this as a guide, suitable apportionment may be madein each particular instance without undue trial and error. If the blendis purposed for use in newsprint ink, or as wire coating, theproportioning may be varied to give a blend oi somewhat lower meltingpoint.

It is desirable that the high-melting coumarone-indene resin blendedwith the still-residue resin should be oi high polymer size, and thatits melting point should exceed 150 C. (ball and ring). Advantage is,however, derived from blending in the high-melting resin, even thoughits melting point should not be so high; provided that it be of apolymer size remotely high with respect to the 6th stage polymers, whichare the highest polymers present in any substantial proportion in thestill residue resin. That is, advantage is to be derived from blendingif the high-melting resin has an average molecular weight exceeding1000, and that its polymer size be considered "remotely high" in thesense that it has no substantial content oi polymers as low as 10thstage polymers.

Wherever, throughout the specification and claims, melting point isgiven without qualification as to the` method used in its determination,it is to be taken for granted that it is determined by the ball and ringprocedure. Where not specifically so stated, proportions are to be takenas based upon parts by weight. By the term total still residue resin Iintend to specify a reasonable approximation to a complete retention ofdimers, and not an absolute retention of them.

Where the term resin is used without qualification in the speciilcationand claims, it is to be taken as coumaroneindene resin; and also theterm coumarone-indene" is used of a highpolymer resin without regard tothe theoretical capacity ory incapacity of coumarone to form polymersas'high as those which indene is capable of forming.

I claim as my invention:

1. The herein described blended coumaroneindene resin composite oi'still residue resin derived primarily by purication and distillation ofthe still residue resultant from the acid purification, neutralizationand distillation of the light oil derived in the by-product coking ofcoal consisting essentially of coumarone-indene dimers andcoumarone-indene polymers in the 3rd, 4th, 5th and 6th stages ofpolymerization, with added high-melting coumarone-indene resinconsisting o polymers in higher than the 10th stage of polymerization;in the blend the proportioning being approximately 25% to 40% dimers,25% to 40% 3rd, 4th, 5th and 6th stage polymers and 20% to 40% addedhigh melting resin, the melting point and proportional inclusion of theadded high-melting resin within the given limits being such as to impartto the blend a melting point approximately as high asV C.

2. The herein described blended coumaroneindene resin composite of stillresidue resin derived primarily by puriiication and distillation of thestill residue resultant from the acid purification, neutralization anddistillation of the light oil derived in the by-product coking of coalconsisting essentially of coumarone-indene dimers and coumarone-indenepolymers in the 3rd, 4th, 5th and 6th stages of polymerization. withadded coumarone-indene polymers in higher than the 10th stage ofpolymerization; in the blend the proportioning being approximately 25%to 40% dimers, 25% to 40% 3rd, 4th, 5th and 6th stage polymers and 20%to 40% added high coumarone-indene polymers.

3. The herein described blended coumaroneindene resin consistingessentially of still residue resin derived primarily by purification anddistillation of the still residue resultant from the acid purication,neutralization and distillation of the light oil derived in thelay-product coking of coal consisting essentially of coumaroneindenedimers and coumarone-indene polymers in the 3rd, 4th, 5th and 6th stagesof polymerization, the said still residue resin containingcoumarone-indene dimers in a quantity of about 50% the weight of thestill residue resin, no more than the initial content of 3rd, 4th, 5thand 6th stage coumarone-indene polymers of the said still residue resin,and an added content of highmarone-indene dimers in a quantity not sub--stantially less than 25% the weight of the still residue resin, no morethan the initial content of 3rd, 4th, 5th and 6th stage polymers of thesaid still residue resin, and an added content of highpolymercoumarone-indene resin melting from about C. upward in a quantity atleast approximately equal to the weight of the coumarone-indene dimers.

5. The herein described blended coumaroneindene resin consistingessentially of still residue resin derived primarily by puriiication anddistillation of the still residue resultant from the acid puriiicatlon,neutralization and distillation of the light oil derived in theby-product coking of coal consisting essentially of coumaroneindenedimers and coumarone-indene polymers in the 3rd, 4th, 5th and 6th stagesof polymerization, the said still residue resin containingcoumarone-indene dimers in a quantity not substantially less than 25%the weight of the still residue resin, no more than the initial contentof 3rd, 4th, 5th and 6th stage polymers of the said still residue resin,and an added content of high-polymer coumarone-indene resin melting fromabout 150 C. upward in a quantity approximately as great as thecoumarone-indene dimer content of the still residue is capable ofplasticizing.

FRANK W. CORKERY.

